Island



I (No Model.)

A. MGPHERSON.

STEAM ENGINE.

No. 446,888. Patented Feb. 17,1891,

INK/INTER.-

UNITED STATES PATENT OFFICE.

ALEXANDER MOPHERSON, OF OXFORD, CANADA, ASSIGNOR OF ONE-HALE TO HUTOI-IISON & HUESTIS, OF PROVIDENCE, RHODE ISLAND.

STEAM-ENGINE.

SPECIFICATION forming part of Letters Patent No. 446,838, dated February 17, 1891.

Application filed November 5, 1890. Serial No. 370,337; (No model.)

To all whom it may conceive.-

Be it known that I, ALEXANDER MoPHER- SON, of Oxford, in the county of Cumberland, Nova Scotia, Canada, have invented a new and useful Improvement in Steam-Engines; and I hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming part ofthis specification.

This invention has reference to an improvement in devices for regulating and controlling the admission of steam to the steam-cylinder and the exhaust of the steam from the same; and it consists in the peculiar and novel construction of an auxiliary steam-cylinder and the connections between the same, the main steam-valve, and the governor, as will be more fully set forth hereinafter.

Figure 1 is a vertical view, partly in section, of the steam-chest, the auxiliary cylinder, the governor, and connections between the same. Fig. 2 is a horizontal view, partly in section, of the main valve, its connection with the main steam-cylinder, and the auxiliary steam-cylinder by which the main valve is operated.

Similar numbers of reference indicate corresponding parts in both figures.

In the drawings, the number 5 indicates the part of the main steam-engine cylinder containing the usual steam ports or ducts. It is shown in Fig. 2 in connection with the steamchest 6 and slide-valve 7. The slidevalve is reciprocated in the usual manner, it being connected by means of a connecting-rod with the eccentric 9.

The cut-oft valve 8 by which the admission of steam to the ports of the slide-valve is regulated is the valve to which the improvement is applied and which is operated through the auxiliary cylinder controlled by the governor.

The valve-stem 10, which is secured to the slidevalve, is made tubular and extends through the stuffing-box 11, outside of which the tubular valve-stem 10 is secured to the yoke 12, the other end of which is secured to the extension 13 of the valve-stem supported in the slide-rest 14:. The connecting rod 15 is pivotally secured to the solid extension 13 of the valve-stem at one end and to the occentric-straps 10 at the other end. The yoke 12 thus makes a break in the lineal continuity of the valve-stein and, if desired, a double yoke or an open parallelogram having two longitudinal side bars may be used. Within the ofiset made by the yoke 12 the cylinder 17 is firmly secured, so that the axis of the same is on a line with the axis of the tubular valve-stem 10. The piston 18 in the cylin- 6o der 17 is connected with the cut-off valve 8 by means of the valve-rod 19 passingthrough the stuffing-box 20 on the cylinder 17 and the stuffing-box 21 on the end of the tubular valve-stem 10. v

The valve-chest 22 on the cylinder 17 is connected with the tubular valve-stem 10 by. the pipe 23, and thus with the steam-chest 6, so that steam of the same pressure will be maintained in both the steam-chests, and steam'will be supplied'to the steam-chest 22 and the cylinder 17 from the steam-chest 6.

The centrifugal governor 24: is connected by the link 25 with the lateral arm of the three-arm rocking-lever 26. To the upper end 7 5 of the vertical arm of the rocking-lever 26 the slide-rod 27 is pivotally secured. The 0pposite end of the slide-rod is provided with the inclined cam 28. To the lower end of the vertical arm of the rocking-lever 26 the slide 29 is pivotally secured. The slide-rod 29 is supported in a way formed on the bracket 30, and its end is formed into a hook, terminating in the inclined cam 31. The slide-rod 27 is supported in a bearing formed in a vertical extension of the slide-rod 29. The cylinder 17 is connected with the steam-chest 22 by four ports or ducts. Two of these are the steamports and terminate at the extreme ends of the cylinders. The other two ports are the exhaust-ports. These are placedashort distance from the extreme end of the cylinder, and connect the cylinder with the arched transverse opening in the slide-valve 32, which opening is connected in any desired manner 5 with an exhaust-pipe, so that in its reciprocation the piston 18 near each end of the strokewill close the exhaust-port, and the confined steam will act as a cushion on the piston of the auxiliary cylinder by which the cutoff valve is operated.

The steam and the exhaust-ports of the cylinder 17 are controlled by the valve 23:2, which is operated by the lever 33, secured to a rock-shaft, on the outer end of which the double tappetdever 3t is secured.

The operation of the improved automatic cut-oil is controlled directly by the governor 2i. \Yhen the speed decreases, the balls descend and the link 25 moves the lateral arm of the three-arm rocking-lever downward, and thus draws the slide-rod 27 forward and pushes the slide-rod 29 backward, thus increasing the distance between the inclined cams 2S and 31. The auxiliary engine and the steam-chest 2:3, with the double tappet-lever 3t, reciprocate with the valve-rod 10, moved by the eccentric 9. The valve is operated when one of the ends of the tappet-lever 31: comes in contact with either the cam 28 or 31, and the farther these cams are apart the longer is the interval between the movementof the valve and the longer will the cut-elf valve 8 leave the port in the slide-valve open, and consequently the greater will be the supply of steam to the main cylinder. If by this extra allowance of steam the speed of the piston is increased, the balls of the governor are at once raised, the cams 31 and 38 are brought nearer together, and instantly at the returnstroke the tappet-lever will move the valve 32 so as to admit steam to the opposite end of the cylinder 17, and thus move the cut-oil valve to cut off the steam quicker than at the opposite end of the stroke. A steam-engine can thusbe accurately regulated, so thatthe slightest variation in speed will automatically increase or decrease the amount of steam supplied and will cut off the steam instantaneously or as quickly as steam under full pressure can move the piston in the auxiliary engine, thereby preventing all wire-drawing of thestcam.

I do not wish to confine myself to the exact form of centrifugal governor shown in the drawings, or to the exact mechanism connecting the slide-rods 2T andif) with the governor, as the slides may be operated in any other manner it better adapted to the special conditions or to the operation of any other form of governor.

Having thus described my invention, 1 claim as new and desire to secure by Letters Patent- 1. in a steam-engine, the combination, with the main valve controlling the admission of steam to the cylinder, of a cut-off valve, an auxiliary engine the piston-rod of which is secured to the cut-off valve, a valve regulating the admission of steam to the auxiliary engine, a doublc-ended tappet-lever connected with and operating the valve of the auxiliary engine, and mechanism intermediate the engine-governor and the tappet-lever, as described.

2. In a steam-engine, the combination, with the rod or stem connected with the valvccontrolling the admission and the exhaust of the steam, of an auxiliary steam-engine secured to and moving with the valve rod or stem, a cut-off valve operated by the auxiliary engine, and mechanism, substantially as described, for controlling the ad mission of steam to the auxiliary engine, as described.

The combination, with the slide-valve of a steanrengine, of a tubular val ve rod or stem, an auxiliary steamenginc secured to and carried by the valve-rod, a cut-off valve connected with the piston of the auxiliary steamengine and operated by the same, a governor, and mechanism, substantially as described, intermediate the governor and the cylinder of the auxiliary engine, constructed to regulate the admission of steam to the auxiliary engine, as described.

4. The combination, with the ports of a steam'engine and the valve 7, of the tubular valve-stem 10, the cut-off valve 8, the auxiliary engine, the piston 18, the rod 19, secured to the piston 18, and the cut-oil valve 8, the steam-chest 22 of the auxiliary engine, the connecting-pipe 223, a centrifugal governor, and the valve-operating mechanism interme diate the auxiliary engine and the governor, as described.

5. In a steam-engine,the combination,with the steam-ports of the engine-cylinder, the valve 7 and cut-off valve 8, and an auxiliary engine secured to and moving with the stem or rod of the main valve and connected with and operating the cut-off valve, of the governor 24-, the slide-rods 27 and 2!), and the tappet-lcver 35, constructed to regulate the speed of the engine, as described.

In witness whereof I have hereunto set my hand.

ALEXANDER MQPIIERSON. Witnesses:

A. M. 111mm: v, CHARLES )IoNmLL. 

